Tuesday, April 5, 2016

What is it that makes a great smartphone display?

A display makes or breaks a smartphone. So a good display is of the highest importance to a smartphone as it is the primary means of how you interact with your smartphone. But, over the years, different display technologies have popped up, each with their own set of features and resolutions. If you’d like to learn more about smartphone displays, this is the article for you.

The first question that needs to be tackled is:

How does a smartphone display panel work?

The basic building blocks of displays are pixels. The resolution and type of each display is based on the number of pixels there are as well as the physical size of the display. These pixels in turn are made out of three individual color sectors: red, green, and blue. So, when a display does its job, each of the colors in a pixel light up really fast or turn off in the same manner to provide you with a moving image. And the way in which these pixels light up determines the type of display.

But there are also a number of other factors to consider when checking out a good display. Namely: the resolution (along with the type of the display). Other factors like viewing angles and color saturation help determine how good a display is.

So, let’s begin with the first major factor: resolution.

What is resolution?

Resolution can be defined as the number of pixels that a screen possesses which is expressed by the number of pixels on the horizontal axis times the number of pixels on the vertical axis. For example: 1280 x 720. The clarity of a display is defined by its resolution and its physical size. Pixel density is the measure for how good a display is by combining the above mentioned values.What is pixel density?

Pixel density can be defined as the number of pixels per unit length. Usually it’s taken in terms of PPI, or Pixel Per Inch. Obviously, this defines the number of pixels in one inch of the display. It’s pretty simple, really: higher pixel density equals a better display. That’s all you need to know, aside from this…

The value of pixel density can be tweaked quite easily. All you need to do isreduce the size of the display. Theoretically speaking, you’ll have the same number of pixels crammed into a smaller space (effectively making for a better display).

The most efficient pixel density, according to Apple, is around 300 ppi. This is because 300 ppi represents a tipping point for the human eye where we can no longer make out individual pixels — the image appears as clear as it can to us. Of course this stopped manufacturers from churning out smartphones with higher ppi values.

So, let’s get started with the major resolutions present in the myriad of displays present in smartphones, shall we?

HD (720p)

HD — or High Definition — displays have a resolution of 1,280 x 720 pixels. As I mentioned before, the size of the screen can be anything, however, the amount of pixels in that display should be 1,280 x 720. HD display resolution sits around 720p, so that’s what it’s commonly called.

FHD (1080p)

As we move up the list, we get FHD, or Full High Definition. Displays at this resolution are around 1,920 x 1,280 pixels. FHD is at 1080p in resolution, hence, giving it its name.

QHD (2K)

QHD is an abbreviation for Quad High Definition and it’s exactly what it sounds like. It is basically HD times four. In layman’s terms, it is the pixels of 4 HD displays, compressed into one of the same size. Its resolution is around 2,560 x 1,440 pixels. You might also see it called 2K.

UHD (4K)

Now this is where it gets interesting. The highest number of pixels in any screen so far is around 4,096 x 2,160. That’s enormous! However, we can divide 4K into two specific resolutions. Ultra HD at around 3,860 x 2,160 pixels and OG 4K displays sit at 4,096 x 2,160 pixels. This is usually called 4K (or 2160p).

Next, let’s talk about the different types of displays. At this point we’ve only covered the various resolutions smartphones have to offer. But there are also different screen technologies that utilize them.

LCD

LCDs, or Liquid Crystal Displays, are quite commonly used in smartphones. They’re made up of something called liquid crystals (obviously) which control how the screen works. In the back of the display is a backlight which shoots light through a layer of liquid crystals which are covered in pixels (which each contain those three colored building blocks mentioned earlier: red, green and blue). When the backlight powers on, the liquid crystals acts as a polarizing lens and light up only select pixels which produces a moving image.

LCD displays are divided into two. LCD TFT displays and LCD IPS displays. Without going in depth, the main difference between the two is the arrangement of the liquid crystals between the pixels and the backlight; but that makes all the difference. Generally, LCD IPS displays are better than LCD TFT displays because they have better color reproduction and great viewing angles.

OLED

OLED displays are gaining in popularity and come in several varieties.

OLED, or Organic LEDs, are organic screens that produce light when electricity is passed through it. These kinds of display are relatively thin, provide crispier images with a punch of color and also consume less power.

What about AMOLED, then?

AMOLED displays, or Active Matrix OLEDs, have a built in transistor which basically allows for precise, accurate, and fast lighting of pixels. Samsung actually has its own line of displays called Super AMOLED displays. Samsung’s offering is similar to traditional AMOLED display technology but adds a greater number of subpixels for far more accurate color reproduction.

Now you know what makes for a good smartphone display. Phew, that was a lot of information. Hopefully, now you’re smarter than yesterday!